A multiresidue method was developed and validated for simultaneous analysis of 5 families of mycotoxins in corn grain. Deoxynivalenol (DON); aflatoxins B1, B2, G1, G2; ochratoxin A; zearalenone; and fumonisins FB1 and FB2 are extracted from corn grain samples with watermethanol, and extracts are cleaned up using immunoaffinity and solid-phase extraction columns. The column high-performance liquid chromatographic method uses postcolumn photochemical derivatization for detection of aflatoxins and derivatization with o-phthalaldehyde for detection of fumonisins. Mean recoveries and relative standard deviation values () over studied fortification levels for the chosen matrixes were: DON 89.9, 8.7; aflatoxin B1 85, 9.4; aflatoxin B2 82.4, 9.7; aflatoxin G1 74.8, 13.5; aflatoxin G2 79.2, 10.0; fumonisin B1 96.2, 8.0; fumonisin B2 84.5, 6.4; zearalenone 91.7, 11.5; and ochratoxin A 87.4, 15.8. The method performance criteria, including specificity, accuracy, repeatability, operational range, and detection limits, were found to be within specifications set by the Feed Additives and Contaminants Group of the AOAC Agricultural Materials Community.

An HPLC method with postcolumn derivatization was developed and validated for the determination of theanine content in tea dietary ingredients and supplements. A variety of common commercially available supplement forms such as powders, liquid tinctures, tablets, softgels, and gelcaps, as well as three National Institute of Standards and Technology Camellia sinensis Standard Reference Materials were investigated in the study. A simple extraction procedure using citrate buffer at pH 2.2 allowed for the analysis of theanine without additional cleanup or concentration steps, even at low ppm levels. Theanine was separated from other naturally occurring amino acids using a cation-exchange column and detected using a UV-Vis detector after derivatization with ninhydrin reagent. A single-laboratory validation demonstrated that specificity, accuracy, precision, and other method performance parameters have met the requirements set for theanine analysis by the AOAC Stakeholder Panel on Dietary Supplements.

The Alpha amylase breaks down long chain carbohydrates and that's why it is very useful in food and pharmaceutical industries. The aim of the present work is to extract and characterize the Alpha amylase from germinated Mat beans, for optimum pH and temperature for activity and stability, effect of metal ions, optimum substrate concentration, Km and V max. Mat beans were germinated and then extracted with Acetate buffer (pH 5.0). The amylase assay was based on the reduction in blue color intensity resulting from enzyme hydrolysis of starch. For optimization of pH for stability, buffer solutions from pH range of 3.5 to 10.0 were prepared. For determination of optimum temperature, the range used was 35 o C to 65 o C. Substrate solutions in range of 0.1% to 4.0% were prepared for optimum substrate concentration. Mat beans germinated for 3 days show maximum enzymatic activity (65.79U/ml). 95% of the original activity was retained in the pH range 7.0 to 8.0. The maximum activity of an enzyme was found to be at 55 C. 10mM Ca 2+ stimulated the enzyme activity up to 123%. Optimum substrate concentration was found to be 1.5%. Km was found to be 2.0 mM, and Vmax 100.0 nm/min. Alpha amylase extracted from germinated Mat beans follows Michaelis-Menten equation. It can be concluded that Mat bean is a good source of Alpha amylase and this enzyme could find promising application of hydrolysis of starch.

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